Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash payments :
Interest paid during the year	$ 33.4	$ 40.0	$ 41.6
Income taxes paid during the year	203.4	143.7	77.4
Non cash investing and financing activities :
Equipment purchased with debt	2.5	8.9	9.1
Acquisition of intangible assets with debt assets from BFDS	0	0	10.7
Exchange of available-for-sale securities for an investment in a pooled fund	0	0	21.7
Charitable contribution of marketable securities	$ 0	$ 8.9	$ 0